Actually, a few standards would qualify.
According to
this site, “Silent Night” was written by Austrians Joseph Mohr and Franz Gruber (it’s a fine line between Austrians and Germans, especially since they speak German).
This site has the German pronunciation of the lyrics simplified for English speakers.
http://cnx.rice.edu/content/m11029/latest/
Mendelssohn wrote the music for “Hark! The Herald Angels Sing,” although the words were written by Charles Wesley.
“Oh Christmas Tree” was written by Ernst Anschutz.
http://german.about.com/library/blotannenb.htm
Poke around that site and you’ll find German lyrics for other Christmas carols.
Hope this helps.
Regards,
Wayne A. Pflughaupt